1. Field
This invention relates to optically assisted surgical procedures. More particularly, this invention provides novel apparatus and methods for conducting minimally invasive endoscopic diagnostic and therapeutic procedures.
2. State of the Art
Endoscopic methods and instruments for accessing body cavities, while well developed, do not adequately address several specific problems. Certain such instruments, as applied for diagnostic purposes, are regarded as being undesirably invasive. Others presuppose applications which are procedurally convoluted and prohibitively time-consuming. Some procedures require excessively complicated and costly structure and imaging components.
Typical endoscopic instruments and their customary applications include hysteroscopes for intra-uterine evaluation, amnioscopes for direct fetal diagnostics within the amniotic sac, falloposcopes for fertility enhancement, cystoscopes for bladder inspection, and ureteroscopes for renal access, general fiberscopes and the like. In some respects, trocar cannulae in conjunction with abdominal insufflation and other surgical equipment under endoscopic visualization may be considered as being related to the art of endoscopy.
Standard among existing endoscopic devices are eyepieces which are adaptable to varying focal depths. These eyepieces are characteristically fixed in position relative to the body of the scope. Fixed eyepieces limit the breadth and positing of the endoscope, imposing concomitant discomfort to the user and potential disruption at the insertion site. On average, for example, hysteroscopic diagnostic procedures have a duration of at least 5 minutes. Beyond the first few minutes of a procedure, the examiner ordinarily experiences discomfort, because the fixed position of the eyepiece restricts the examiner to a crouched position.
Conventional endoscopes may be either flexible or rigid in character. Currently available flexible endoscopes have outside diameters as small as 3.6 millimeters while conventional rigid endoscopes have outside diameters in the range of 6 millimeters to approximately 12 millimeters. The smaller, flexible endoscopes offer directional capability at their distal, leading end tips. They are by their nature, however, difficult to direct during insertion into a desired site. After surgical use, it is difficult to assure adequate and cost-effective sterility, particularly along the entire length of the channels characteristically incorporated within such flexible endoscopes for the delivery of distention media.
Endoscopes of relatively large outside diameter, whether rigid or flexible, present the disadvantage of invasive and obtrusive size. Preparatory procedures are required to address the potential for discomfort, infection due to inadequate sterilization following multiple procedures, and localized tissue trauma. Rigid scopes are inherently limited in their achievable distal orientations.
Common practice prescribes a protocol of local or general anesthetic preceding an hysteroscopic procedure. Several practical disadvantages, including cost and coordination requirements, arise from the involvement of anesthesia in hysteroscopy. The side-effects and risks associated with anesthesiological practice are also of concern. While some existing flexible hysteroscopes of smaller outside diameter avoid the disadvantages of anesthetization, the other disadvantages associated with flexible endoscopes may be especially pronounced in the context of hysteroscopy.
Conventional hysteroscopic practice involves steps to dilate the internal diameter of the cervix. It is desirable to minimize frictional resistance between the outside diameter of the hysteroscope and the inside periphery of the cervical orifice during insertion of the hysteroscope. Dilation of the cervical orifice has in most cases heretofore been accomplished by insertion of a strand of a substance, known as laminaria, derived from ground seaweed. The laminaria, following waiting periods not uncommonly in excess of 72 hours, gradually absorbs surrounding moisture and thereby expands to a diameter adequate for reception of a conventional hysteroscopic apparatus. It is necessary that dilation occur gradually to minimize discomfort. There are self-evident disadvantages to the laminaria dilation procedure. The procedure involves the cost of insertion and eventual removal under controlled conditions. An inordinate time commitment is required of the patient. This procedure also presents the possibilities of over expansion of the cervix and internal or external dislodging of the laminaria.
Another problem commonly encountered during hysteroscopic diagnostics is interference from source conduits for distention media. These conduits are typically stiff. When affixed in conventionally immovable relation to the body of hysteroscopic instruments, they tend to restrict the ease with which the instruments can be manipulated through the cervix and within the uterus.
A majority of hysteroscopic instruments comprise rigid cannula, through which illumination and image fibers are placed. The tips of the fibers protrude only minimally beyond the distal tip of the cannula. Because of the pear-like configuration and size of a distended uterus, most positions on the inner walls of the uterus can be acceptably visualized at the eyepiece despite employment of a rigid distal tip on the instrument. However, those portions of the inner uterine walls immediately adjacent the fallopian tubes can be only peripherally and poorly accessed. To achieve even this limited examination requires forcing the hysteroscopic instrument at an abrupt angle against the internal side of the cervical orifice opposite the internal wall of the uterus sought to be visualized. Patient discomfort and tissue damage are the probable consequences of such procedures.
Cost-effective and reliable sterilization of hysteroscopes has heretofore not been achieved. Contaminants tend to accumulate within the source conduit which conveys the distention medium. Microorganisms migrate and propagate within the elongate cannula. There is accordingly a degree of uncertainty in the efficacy of conventional sterilization procedures as applied to these instruments. Antibiotics utilized for disinfection in this context, aside from being extremely noxious and offensive to a user, are most often used as a soaking solution for roughly 20 minutes rather than the several hours necessary to more certainly assure adequate sterilization. Similarly, thorough cleansing manipulations applied to the optics themselves tend to cause fragmentation of the optics. Compromised optical clarity disrupts the quality of the light and visual images conveyed through the instrument.
It is currently normal practice for hysteroscopes to be non-disposable, primarily because of their sizable cost, and because their respective configurations have not readily lent themselves to fashioning them with disposable parts.
A need, therefore, exists in the art for an improved fiberscopic device structured to avoid the limitations and shortcoming of currently available such devices. Specifically, a need exists for an endoscopic device which avoids many of the practical disadvantages normally associated with general and local anesthetics. Further, a need exists in the art for an endoscopic device which is capable of maintaining some frictional resistance between the device and the insertion site without dilation of the insertion site. A need also exists in the art for a endoscopic device which incorporates mechanical and ergonomic enhancements to facilitate ease and precision of use for the user and comfort, safety, convenience and cost-effectiveness of use for the patient. There is a particular need for a structure which enables improved sterilization of reusable parts and facile disposability of single-use parts.